Reliability of an isometric and isokinetic strength testing protocol of the knee and ankle in young adults

From surgery to functional capacity: muscle strength modifications in women post sleeve gastrectomy

BACKGROUND

Severe obesity is characterized by excessive accumulation of fat generating a general health decline. Multidisciplinary treatment of obesity leads to significant weight loss in a few patients; therefore, many incur bariatric surgery. The main purpose of the study is to evaluate changes in functional capacity of people with obesity undergoing bariatric surgery and, in parallel, to correlate pre-surgery functional capacity with weight loss to improve exercise prescription during pre-operatory stage.

METHODS

sixty women with diagnosed obesity were included. Maximal oxygen consumption, upper and lower limb strength and level of physical activity were recorded 1 month before and 6 months after sleeve gastrectomy.

RESULTS

significant reduction on body weight (-30.1 kg) and Body Mass Index (-11.4 kg/m2) were highlighted after surgery. Absolute grip strength decreased significantly (-1.1 kg), while body weight normalized grip and lower limb strength increased significantly. The level of physical activity increased especially in leisure time (+ 593 METs/week) and active transport (+ 189.3 METs/week). Pre-surgery BMI and age predicted the amount of weight loss after surgery.

CONCLUSIONS

Sleeve gastrectomy induces a reduction of muscle strength despite the increase of time spent in physical activity. Further research is necessary to integrate these results with data on body composition, and objective evaluation of physical activity level to define useful information for exercise prescription in terms of surgery pre-habilitation.

TRIAL REGISTRATION

Padova University Hospital Board (protocol n. 2027 dated January 12, 2017).

Early ACL reconstruction shows an improved recovery of isokinetic thigh muscle strength compared to delayed or chronic cases

INTRODUCTION

The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the delay of surgery (∆ between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction.

MATERIALS AND METHODS

In a retrospective cohort study, all patients with ACL ruptures between 03/2015 and 12/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5-7 months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (∆ < 42 days), DELAYED reconstruction (∆42-180d), and CHRONIC (∆ > 180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60°/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q) ratio), and the corresponding limb symmetry indices.

RESULTS

n = 444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65 ± 0.45 to 1.62 ± 0.52 to 1.51 ± 0.5 Nm/kg resp.) and flexion (1.22 ± 0.29 to 1.18 ± 0.3 to 1.13 ± 0.31 Nm/kg resp.) strength on the ACL reconstructed leg. This general loss in periarticular strength was already apparent in the preoperative performance even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension p = 0.001, flexion p = .02) and CHRONIC (extension p = 0.005, flexion p < 0.001). Also, there were significantly higher values for H/Q ratio in the injured leg across all groups where the H/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values.

CONCLUSIONS

With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12 weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg.

LEVEL OF EVIDENCE

III, retrospective cohort study.

General, spinal or regional anaesthesia does not affect strength performance 6 months after ACL reconstruction

PURPOSE

The recovery of strength is a key element in successfully returning to sports after ACL reconstruction. The type of anaesthesia has been suspected an influential factor in the post-operative recovery of muscle function.

METHODS

In this retrospective analysis, n = 442 consecutive patients undergoing primary isolated ACL reconstruction using a hamstring autograft were analysed by pre- and post-operative isokinetic tests in a single orthopaedic centre. These were subdivided into four cohorts: (1) general anaesthesia (n = 47), (2) general anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 37), (3) spinal anaesthesia (n = 169) and (4) spinal anaesthesia with prolonged (48 h) on-demand femoral nerve block (n = 185). Primary outcome was the change from pre- to post-operative isokinetic strength during knee extension and flexion.

RESULTS

Using one-way ANOVA, there was no significant influence of the type of anaesthesia. The main effect of anaesthesia on change in extension forces was not significant, and effect sizes were very small (n.s.). Similarly, the main effect of anaesthesia on change in flexion forces was statistically not significant (n.s.).

CONCLUSIONS

The findings of this study support the interpretation that the type of anaesthesia has no significant effect on the ability to recover thigh muscle strength 6 months after isolated hamstring ACL reconstruction. With regard to the recovery of athletic performance and return-to-sports testing criteria, there is no reason to avoid regional anaesthesia.

LEVEL OF EVIDENCE

III.

Functional deficits in chronic mechanical ankle instability

BACKGROUND

The interaction of functional and mechanical deficits in chronic ankle instability remains a major issue in current research. After an index sprain, some patients develop sufficient coping strategies, while others require mechanical support. This study aimed to analyze persisting functional deficits in mechanically unstable ankles requiring operative stabilization.

METHODS

We retrospectively analyzed the functional testing of 43 patients suffering from chronic, unilateral mechanical ankle instability (MAI) and in which long-term conservative treatment had failed. Manual testing and arthroscopy confirmed mechanical instability. The functional testing included balance test, gait analysis, and concentric-concentric, isokinetic strength measurements and was compared between the non-affected and the MAI ankles.

RESULTS

Plantarflexion, supination, and pronation strength was significantly reduced in MAI ankles. A sub-analysis of the strength measurement revealed that in non-MAI ankles, the peak pronation torque was reached earlier during pronation (maximum peak torque angle at 20° vs. 14° of supination, p < 0.001). Furthermore, active range of motion was reduced in dorsiflexion and supination. In balance testing, patients exhibited a significant increased perimeter for the injured ankle (p < 0.02). During gait analysis, we observed an increased external rotation in MAI (8.7 vs. 6.8°, p<0.02).

CONCLUSIONS

This study assesses functional deficits existent in a well-defined population of patients suffering from chronic MAI. Impairments of postural sway, gait asymmetries, and asymmetric isokinetic strength can be observed despite long-term functional treatment. The finding that pronation strength is particularly reduced with the foot in a close-to-accident position indicates potential muscular dysfunction in MAI. Possibly, these deficits alongside the underlying mechanical instability characterize patients requiring mechanical stabilization.